Coating composition and method



United States Patent 3,085,870 CQATING CGMPUSITIQN AND METHOD David B. Sheidahl, Grifith, Ind., and George Entwistle, Chicago, lib, assignors to Sinclair Refining Company, New York, N.Y., a corporation of Maine No Drawing. Filed Sept. 28, 1959, Ser. No. 842,598 6 Claims. (Ci. 106-10) This application is a continuation-in-part of application Serial No. 759,850, filed September 9, 1958, now abandoned.

The present invention concerns a novel supplement for wax-containing coating compositions which imparts long-lasting corrosion inhibiting properties to the composition. The resulting coating composition may be used on enameled metal surfaces as well as chromium-plated or stainless steel surfaces.

Much chrome plating is purely decorative and gives litle long-time corrosion protection. Moisture and corrosive agents seep into voids in the chrome plating and corrode the base metal underneath. The products of corrosion bleed out through the voids and produce an unsightly appearance. As a result, chrome-plated automobile bumpers and other non-enameled metal parts are apt to corrode quite badly especially when exposed to winter-time weather and road conditions. In the winter, salt used for deicing streets, soot, corrosives, and solids in the atmosphere tend to collect on automobiles. Infrequent Washing of automobiles maintains an environment that is conducive to corroding chrome automotive parts and even stainless steel trim.

Stainless steels vary in their resistance to saline water corrosion. The grade often used in automotive trim, while more resistant to saline waters than mild steel, is not as corrosion resistant as desirable. Furthermore, the paint film is often imperfect where the trim is attached and conditions at the juncture of body and trim are ideal for crevice corrosion. The application of conventional paste waxes and liquid polishes to chrome plated and stainless steel parts generally does not provide a film thick enough or impervious enough to keep air, water, and corrodents from either the gaps or cracks in chrome plating or the surfaces of the stainless steel. Neither do they provide adequate protection against crevice corrosion.

It has now been discovered that a corrosion inhibiting supplement for automobile polish, comprising a mixture of an oil-soluble aromatic sulfonate and a fatty acid monoester of sorbitan in particular proportions may be incorporated in commercially available automobile liquid polishes and paste wax compositions to give these coating compositions greatly improved corrosion resisting properties. The supplement can be incorporated in the polishes or waxes in proportions of about 110% by weight, preferably about 2.0-6.5%

The supplement has about 1 10, preferably about lparts by weight, of a sorbitan mono-fatty acid ester and about 1-5 preferably about 1-2 parts by weight of an oil-soluble aromatic sulfonate selected from the group consisting of oil-soluble ammonium aromatic sulfonates and oil-soluble sodium aromatic sulfonates. The sul fonatte is usually avail-able in solution in a petroleum oil such as lubricating oil. This solution frequently contains about 10% by weight of the sulfonate and the lubricating oil can be the native environment in which the sulfouate has been prepared. Where this preferred proportion of sulfonate prevails in the solution the pro- 3,085,370 Patented Apr, 23, 1963 "ice portions of ingredients in the supplement are approximately 5 to 10% of the sulfonate, 5 to 50% of the sorbitan mono-fatty acid ester and 45 to of the high boiling mineral lubricating oil in which the ammonium sulfonate has been prepared.

The fatty acid monoester-s of sorbitan useful in the supplement are obtained by the esterification of sorbitan by fatty acids containing from 6 to 18 carbon atoms. The fatty acids can be those derived from various animal and vegetable oils and fats or synthetic fatty acids. Examples of suitable acids are caproic, caprylic, capric, lauric, myristic, palmitic, oleic, linoleic, linolenic, ricinoleic, stearic and dihydroxy stearic acids. Sorbitan is the partially dehydrated polyhydric alcohol 1,2,3,4,5,6- hexanehexol. The esters can be made by reacting 1 mol of the polyhydric alcohol or 1 mol of the partially dehydrated alcohol with one to three mols of carboxylic acid or carboxylic acid mixtures either in the presence of or absence of a catalyst. The catalyst may be acidic, for example, sulfuric or phosphoric acid, or alkaline, like sodium hydroxide. The ingredients are commingled and heated in a kettle or other container, preferably closed and equipped with suitable agitating means, at a temperature of -300" C. until the reaction reaches the desired stage. It is frequently desirable to maintain an atmosphere of inert gas such as nitrogen or carbon dioxide over the reacting mass or pass the inert gas through the reacting mass in order to assist removal of water and prevent discoloration of the esters formed. The reaction may also be carried out while refluxing hydrocarbon solvent, with means provided for trapping out the water formed. These esters are well known to the art and methods for their preparation have been described, for example, in US. Patent 2,322,820. These esters are commercially available in the Span series. Span 20 is sorbitan monolaurate; Span 40 is sorbitan monopalmitate and Span 60 is sorbitan monoleate. Span 80 is a mixture of sorbitan mono-fatty acids made from commercial fatty acid mixtures and contain sor-bitan monostearate. In addition, these esters are available in less highly refined form in the Atpet series. Atpet 100, for example is a dark red oily liquid having a specific gravity of 0.98 to 1.00, a minimum viscosity at 25 'C. of 900 cp., an acid number less than 7, a hydroxyl number of to 185, a saponification number of 140- 155 and a pour point of 50-85 F. Atpet 200 is a sorbitan partial fatty ester. It is an amber-colored oily liquid having a specific gravity at 25 C. of approximately 1, a viscosity at 25 C. of approximately 1000 cp., an acid number of 4to 8, a hydroxyl number of 180 to 205, a saponification number of 135 to 150, and a poor point of approximately 0 F. Span and Atpet are trademarks of the Atlas Powder Company.

The aromatic sulfonates useful in this invention are the oil-soluble NH -aromatic sulfonates and the oil-soluble sodium aromatic sulfonates of the benzene or naphthalene series, in which the aromatic ring is sulfonated and, in order to impart oil-solubility, the ring preferably also contains one or more alkyl substituents having up to a tot-a1 of twenty carbon atoms. Such sulfonates can be made respectively, by the ammonium hydroxide or sodium hydroxide neutralization of sulfonated laralkyl hydrocarbon's such as dinonyl naphthalene, and include the neutralized sulfonated bottoms from the manufacture of dodecyl-benzene, neolene, etc. fractions. Typical aromatic sulfonates are described for instance in Us. Patent 2,594,- 266. They can be obtained by the reaction of ammonia or sodium hydroxide with sulfuric; acid-treated hydrocarbon oils, commonly known as mahogany acids. Such sulfonates possess appreciable solubility in both water and hydrocarbon oils. Ln manufacturing the supplement of the invention, the sulfonates may be employed as a concentnate in the oil fnorn which they are derived. A typical solution having, for example, a sulfonate concentration of about percent by weight, can be prepared by treating a Mid-Continentneutral oil with four successive dumps of oleum, a total of 120 pounds of the oleum being used for each barrel of oil. Following removal of the separable sludge after the last dump of oleum, the acid oil is blown with air to remove sulfur dioxide and settled to remove substantially the last trace of sludge. Thereafter the oil is mixed with 0.5 percent by weight of water and neutralized with an excess of anhydrous ammonia. Finally the oil is heated to a tempenature of 280 F. to dehydrate it, and filtered to obtain the product.

Although the ammonium mahogany sulfonates and sodium mahogany sulfon-ates are advantageously employed in the oil solution in which they are prepared, the sulrfonates can be recovered by extraction with :a low molecular weight alcohol, such as isopropanol or ethanol, followed by distillation for use in the oil-free form. In these circumstances the sulfonate may comprise about 9 to about 65% of the supplement of the invention with the rest sorbit-an mono-fatty acid ester. The distillation'pro cedure is disclosed in U.S. Patent No. 2,461,371. Aniline or a lower molecular weight oil-soluble alcohol, such as isopropanol is advantageously added to the sulfon'ate solution in small amounts to improve the stability thereof. Such ammonium mahogany sulfonate solutions of greater stability are disclosed in U.S. Patent Nos. 2,522,518 and 5,522,519.

The two ingredients of the supplement may be incorporated in commercial wax-containing liquid or paste waxes in. minor amountsseparately or as a blend. The resulting compositions contain preferably 0.252% sorbitan mono-fatty acid ester and 0.05 1% of the aromatic sulfonate. To add the supplementconstituents as a' blend, Atpet 200, for example, may be easily mixed with the ammonium or sodium mahogany sulfonate oil solution, for example, by heating to 110 to 120 F. with stirring. A blend of 25' percent by weight of Atpet 200 and 75 percent by weight of a 10 percent oil solution of ammonium mahogany sulfonate, for example, is a dark oily mixture with a viscosity similar. to SAE 20 lubricating oil. A spe cial complete formulation has been developed which uses the supplement and. not only provides greatly enhanced corrosion resisting properties, to surfaces to which itis applied, but also greatly enhanced durability of an unexpected nature. This complete formulation is described in copending applicationSerial No. 759,849, filed Septem-. her 9, 1958. n

One of the commercial liquid preparations reported in Tables I and II to which the novel supplement may be added is described in U.S. Patent No. 2,250,667 as fol-. lows:

Percent Gum tragacanth 0.18 Formaldehyde 1.06 Water r 71.04 Methyl cellulose 0.14 Glycerine 2.91 Diatomaceous earth 11.10 Beeswax 0.28 Carnauba wax 0.02 Neutral oil 12.38 Amyl acetate 0.19 Ferric oxide 0.20 Turkey red oil 0.50

4 Another automobile polish tested reportedly has the following ingredients:

Percent Sodium canboxymethyl cellulose 0.75 Neutral oil 13.00 Blown castor oil 0.75 Diatomaceous earth 13.00 Water 69.00 Sulfonated castor oil 0.50 Formaldehyde 0.50 Glycerine 2.00 Paratfin wax 0.50

Still another reported is:

' Percent Dimethyl polysiloxane 1.00 Oxidized microcrystalline wax 3.00 Light petroleum naphtha 96.00

In order to determine the effectiveness of the supplement of the invention, tests were performed on commercially available automotive polishes and wax compositions and on some original formulations containing the supplement.

Such formulations may contain, besides about 1-10% of the supplement, about 1-10% petroleum wax, which may be parafiin or crystalline wax having a melting point of about 125-145 F., 20-98% low-boiling liquid hydrocarbon and 080% water. The low-boiling hydrocarbon is usually one which boils in the gas oil range or below, e.g. kerosene, naphtha, gas oil, etc. An alkylate solvent made byalkylating C -C olefins with isobutane is preferred which may have for example, the following typical physical properties:

Preferably such formulations contain approximately 50-80% water, 1030% low-boiling hydrocarbon solvent, 1-6% of the petroleum wax and 2.0 to 6.5% of the supplement. When such a formulation is to be applied as an aerosol, the Water content is preferably 510% and the low boiling hydrocarbon solvent -95 7 Also if desired, the formulation may contain anti-freeze agents, germicides and anti-oxidants in elfective amounts.

The presence of'an antioxidant is preferred mainly for the reason that it protects the oil components of the novel composition against oxidation. Suitable antioxidants for use in the present invention are the alkyl substituted phenols such as 2,6-ditertiary butyl, 4-methyl phenol; 2,4,6-tritertiary butyl phenol; ortho tertiary butyl phenol; alkyl substituted nitrogen-containing phenols such as n,n butyl p-aminophenol; isobutyl-p-aminophenol and n,n,di-secondary butyl phenylene diamine. The above antioxidants are to be considered as merely exemplary and as not limiting the use of other antioxidants that are effective in hydrocarbons. I

Use of a germici-de is preferred for the purpose of protecting the sulfonate component of the present invention against attack from bacteria. The germicides useful in our invention are those effective against bacteria known as the sulfate reducingior anaerobic type. The germicides include but are not limited to the following types: halogens, phenols, heavy metal salts, acids triphenylmethane dyes, amines and aldehydes. By a halogen type germicide we mean to include halogens such as iodine and organic halogen compounds such as organic chloramines, e.g. Chloramine-T," a commercial germicide in which the active ingredient is sodium paratoluene sulfonchloramide, and chlorobenzenes, e.g., Cuniphen 2722, a commercial germicide in which the active ingredient is 2,2-methylenebis (4-chlorophenol). By a phenol type germicide we mean to include phenols such as ortho-cresol and thymol (1-methyl-3-hydroxy-4-isopropylbenzene), and halogenated phenols such as chlorinated phenols, e.g. Dowicide 6, a commercial germicide in which the active ingredient is tetrachlorophenol and Nalco 21-S, a commercial germicide in which the active ingredient is trichlorophenate and sodium pentachlorophenate. By a heavy metal salt type germicide we mean to include heavy metal salts such as copper salts, e.g. Cuprose, a commercial germicide in which the active ingredient is copper citrate, and organic mercury compounds, e.g. mercurochrome. By an acid type germicide we mean to include acids such as boric acid and 2,4,5-trichlorophenoxy acetic acid. Examples of triphenylmethane dye type germicides include dyes such as malachite green. Examples of amine type germicides include amine type compounds such as Nalco X-234, a commercial germicide comprising 1-(2-hydroxyethyl)- l-benzyl-Z-tridecyl imidazolinium nitrite in an alcohol co-solvent. It is non-phenolic and contains no heavy metals. Examples of aldehyde type germicides include formaldehyde.

Although unnecessary, the use of antifreezes in the present invention can be desirable particularly in cold climates. Suitable alcohol antifreezes are the glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol and the lower monohydric alcohols such as methyl, ethyl, propyl and butyl alcohol.

In the preparation of the above water-base formulations, the non-aqueous constituents are mixed at a temperature of at least about 135 F., preferably about 150 F., and the resulting mixture then agitated with water at a temperature of at least about 135 F. It is particularly preferred in these preparations to add slowly about 50 to 80%, more preferably 60 to 70%, water at a temperature about 150 F. to a mixture of the non-aqueous constituents rather than adding the mixture of non-aqueous constituents to the water. When Water is added to the non-aqueous constituents a water-in-oil emulsion results which allows the preparation to coat chrome plate or stainless steel with an inhibitor film that repels water and afiords long lasting protection from rusting. When the non-aqueous constituents are added to the water, however, an oil-in-water emulsion results. Chrome plate and stainless steel coated with this emulsion are more easily washed free of the protective inhibitor film causing rusting to occur more rapidly.

In accordance with the preferred method of the present invention the non-aqueous constituents are first mixed together at a temperature greater than about 135 F. Then the water, heated to a temperature greater than about 135 F. is added to the mixture. It is advantageous that the water he added slowly to assure a waterin-oil emulsion. If added too rapidly an oil-in-water emulsion might result producing an inferior corrosion preventive. ployed have a definite effect on the emulsion stability and corrosion preventive properties of the coating composition of the present invention. The non-aqueous constituents should be heated above about 135 F. to assure solution of the paraffin wax. A temperature of about 150 -F. is generally chosen to make sure complete solution is obtained before the water is introduced. The water when added should be at a temperature above about 135 preferably about 150 F. Formulations wherein the water is less than 135 F. when added are not as stable or as effective as corrosion preventives as the formulations where the water was 135 F. or higher. Furthermore, formulations limited to about 50 to 80% The mixing speeds and temperatures emwater are not only the most stable emulsions but possess best corrosion preventive properties. Also, as will be demonstrated, when faster mixing speeds are used a better product results.

A stable emulsion (S-1) was prepared which contained 2% paraflin wax (M.P. 135-137 F.), 1% Atpet 100, 3% ammonium mahogany sulfonate (10% concentrate in petroleum lubricating oil), 44% low-boiling petroleum hydrocarbon solvent, and 50% water. Mild steel panels, polished to a smooth finish of 6 to 12 micron surface roughness, were coated with the above formulation. The panels were exposed in a JAN-H 792 specification humidity cabinet maintained at F. and 100% relative humidity for 14 days, but showed no rusting. Another formulation (8-2) containing 2% paraflin wax (M.P. -137 R), 1.5% Atpet 100, 0.45% ammonium mahogany sulfonate, about 4% high boiling petroleum hydrocarbon and the rest low-boiling hydrocarbon solvent was applied to test panels and after exposure for 14 days in the same humidity cabinet showed only minor amounts of rust. If the wax content of this formulation was increased to 6% wax, no rusting at all occurred during a comparable exposure period, but the wax content was so high that at room temperature the preparation was solid. A formulation S-4 containing 0.5% of sodium mahogany sulfonate, 2% paraflin wax (M.P. 135137 R), 1% Atpet 200, about 2.5% high boiling petroleum hydrocarbon, about 25% low-boiling hydrocarbon solvent and about 65% water was applied to test panels and after exposure for 14 days in the humidity cabinet test showed no rust. By low-boiling hydrocarbon is meant one which boils in the gas oil range or below, e.g., kerosene, naphtha, gas oil, etc. A preferred hydrocarbon is alkylate sol-vent-the product formed when a C or C olefin is alkylated with isobutane. The high-boiling petroleum hydrocarbon is one of lubricating viscosity and preferably is a Mid-Continent neutral oil.

Chrome-plated automobile license plate fasteners were selected as test specimens for the other tests. Metallographic examination determined the chrome plating to be a typical automotive chrome-plated product as to its thickness and application. The license plate fasteners were used both new and also after prerusting. The prerusted (old) specimens were reconditioned by acid cleaning to a corrosion-product-free surface before application of the polish. Because of a limited supply of stainless steel Buick porthole grilles, most of the testing was done with the automobile license plate fasteners, but tests performed on the stainless steel specimens gave comparable results. The test specimens were exposed until failure, that is, until more than a trace of rust was observed, under three different conditions: (1) The regular MIL-L-315O salt fog cabinet wherein ASTM synthetic sea water is fogged into a cabinet maintained at 95 F.; (2) the same cabinet with the same conditions except deionized water was used instead of the synthetic sea water; and (3) immersion in ASTM synthetic sea water.

ASTM synthetic sea water provides a solution containing inorganic salts in proportions representative of ocean water. The process by which this water is made can be found on page 295 of the November 1957 Book of ASTM Standards on Petroleum Products and Lubricants. This standard synthetic sea water has a pH of 8.2 and contains:

Compound Gms./l.

The formulation 8-3 consisted of an emulsion containing 1% Atpet 100, 3% ammonium mahogany sulfonate concentrate in petroleum lubricating oil), 2 parafiin Wax (M.P. 135-137 F.), 44% low-boiling petroleum hydrocarbon solvent and 50% water. This formulation and commercial automotive polishes with and without the supplement of the invention were compared with each other by coating a chrome-plated automobile license plate fastener with each subjecting it to the test conditons described.

Table I reports the corrosive efiects of the test conditions on a license plate fastener which was not given any additional polish coating as well as the elfects of the addition of 4% of the supplement on commercially available liquid automobile polishes and paste waxes. These commercial automobile waxes and polishes are identified in the table below as A3, B2, etc., the brands of the same manufacturer being given the same letter and different numbers. Liquid polishes have been given odd numbers, while paste waxes are given even numbers.

TABLE I It is apparent from these test results that wax-containing coating compositions in liquid or paste form, containing the supplement of the present invention, can impart great corrosion resistance to chrome-plated automotive parts. The wax may be a hydrocarbon or an ester-type wax.

To illustrate the advantages of adding water to the non-aqueous constituents in accordance with the preferred method of preparation rather than the nonaqueous constituents to the water the following examples are included.

Example I Formulations containing 2% parafiin wax (135-137" F., M.P.), 4% of a mixture composed of 75% of a solution containing 10% ammonium mahogany sulfonate in the petroleum lubricating oil in which it was manufactured and Atpet 200, 4% :boiled linseed oil, various amounts of water, with the balance alkylate' solvent were prepared either by adding the non-aqueous constituents to the water or adding the water to the non-aqueous Chrome automotive part failure time, days Salt fog Water tog Salt water immersion Mild steel panels, percent rusted at 14 days 1 Test specimen New Old New Old New Old N 0 Yes 4% supplement added No Yes No Yes No No Yes No Yes No Yes Coating composition' B2 paste 1 MIL-C-8188B specs; panels polished to a 6-12 micron surface roughness and exposed at 120 F. and 100% relative humidity in a .TANH 792 spec cabinet.

2 No rust or only a trace of rust when test was discontinued.

Formulation 8-5, an emulsion of water, 63% alkylate solvent, 2% paraflin wax (M.P. 130-132 F.), 3% ammonium mahogany sulfonate concentrate 10% sulfonate in petroleum lubricating oil) and 1% Span 80, andformulation 8-6, an emulsion of water, 45.5% alkylate solvent, 3% paraffin wax having a melting point of 138140 F., 0.5% Span 20, 1% ammonium mahogany sulfonate' (10% in petroleum lubricating oil) give satisfactory performance in preventing corrosion of chromium-plated and stainless steel automotive parts. Formulation 8-7 is an emulsion of 1% Atpet 200, 3% ammonium mahogany sulfonate (10% in petroleum lubricating oil), 4% boiled linseed oil, 2% paraflin rwax, 25 low-boiling petroleum hydrocarbon and water.

constituents. In all cases the non-aqueous constituents were mixed together at 150 F. and the temperature of both the water and non-aqueous constituents before admixture was -l50 F. Mixing of the non-aqueous constituents and water was conducted at a speed of 12,000 r.p.m. and continued until the temperature fell to 130 F. These formulations were compared with each other by 1) coating metal panels with the diiferent formulations and subjecting the panels to the regular MIL-L- 3150- salt fog cabinet test wherein ASTM synthetic sea water is fogged into -a cabinet maintained at 95 F. and (2) by measuring the percent of separation of water and oil from the formulation after three weeks of storage.

The results areillustrated in Table II.

TABLE II Water-in-oil emulsion Oil-in-water emulsion Three weeks MIL-L- Three weeks MIL-L- Percent water storage, percent 3150, salt storage, percent 3150, salt used Sample separated fog results, Sample separated iog results,

82 percent #982- percent rust at 72 rust at 72 Water Oil hours Water Oil hours 249 2 5 5 250 45 5 35 166 2 2 3 172 35 Trace 10 165 None 2 None 171 25 Trace 1 35 157 None 7 1 158 20 Trace Z 159 None 10 6 160 15 Trace 2 75 161 None 15 25 162 10 Trace 2 163 None 20 1 50 164 5 Trace 2 35 2 Test stopped at 24 hours.

9 Example II A water-in-oil emulsion containing 2% paraffin wax (135-137 F., M.P.), 4% of a mixture composed of 75% of a solution containing 10% of ammonium mahogany protection is afforded when the water is added to the non-aqueous constituents than when the reverse procedure is used. The preparation containing 65% water when prepared by adding water to the oil protected the mild sulfonate in the petroleum lubricating oil in which it 5 staid Panels 72 hours the 15:0 i fog F was made and 25% Atpet 200 4% boiled linseed oil, while the same formulation prepared by adding the oil to vafiqus amounts of water ranging from 25 to 80% with the water allowed the panels to rust 35% in 48 hours. the balance" alkylate solvent were prepared by adding when other Water 50% 9 are water to the non aqueous constituents as described in present the diffedrences 1n corrosion protection are also to pronounce Example I. As in Example I the formulations were given 10 qm the 3 week storage stability and the salt fog cabinet test. The Q of Tilble H demonstfates i 65 Water These results are given in Table HI. content 1s the optimum for emulsion stability as well as TABLE III corrosion preventive qualities. As the content of water decreases or increases both the emulsion stability and cor- 15 rosion preventive qualities worsen. For optimum stability Percent ggg gng gf and activity the water content should be about 55 to 80% sample #982- water Separated resuits, The effects of mixing speeds and temperatures are eviused pa e dent from Tables III and IV. The formulations in Table water 011 III wherein the water was less than 135 F. when added 20 were not as stable or as eifective as corrosion preventive-s 8o 2 5 5 as the formulations where the water was 135 F. or g higher. -It is demonstrated in Table IV that when faster 60 gone 7 1 mixing speeds are used a better product results. 55 10 6 50 25 Example V 45 None 50 3g gone 28 .38 Formulations containing 2% paraffin wax (135137 E, M.P.), 0.5 of the sulfonate indicated below in petroleum lubricating oil, 25% Atpet 200, 4% boiled lin- 1 Test stopped at 48 hours 2 Test stopped at 24 hours seed oil, 65 water with the balance alkylate solvent was Example III 30 prepared by adding the water to the non-aqueous con- The formulation of Example II having 65% water and stituents. Metal panels were coated with each of the 25 alkylate solvent was prepared in accordance with formulations and subjected to the salt fog cabinet test. the method of Example II but using water of various The results were as follows: grlrlrlpgraltuisblgulrglg formulation. The test results are r TABLE SALT FOG TEST 1 TABLE IV 30 RESULTS AND STABILITY INSPECTION Percent of panel rusted at- Percent oil Te t e, F. St b'l't MIL-L-3l50 mpera ur 3 we eirs salt fog test sulronate gt iii oi Sample No.982- Storage results. p 24 hours 48 hours 72 hours weeks Water Hydropercent cent rust at 40 carbon oil sepa- 72 hours rated ZED-119 1 None None None 2 RD-119 1 e 15 10 C-base 3 70 75 150 5 10 NaSul ammonium sulio- 100 150 4 3 hate 4 "I 50 125 150 3 2 Bryton ammonium sulio- 135 150 2 None note 10 30 150 150 2 e Na aromatic sulionate 2 4 7 3 Example IV nultgZi ggnfzentratltleirgmiglglgisug rnglogany sulfonate in Mid-Continent a l om it C 1 UV Formulations containing 2% parafiin wax (135437 i gg z ggg ggfifi fig g ggafi ga Sulionate in Sweet Texas F- MJ'PJ, 4% of a mixture of 75% of a Solution 3 Oil-soluble sulfonic acid prepared by the sulionation oi the bottoms mi i ammonium mahogany lf t i th Petroleum produced in the manufacture of monododecyl benzene which bottoms lubricating oil in which it was made and 25% Atpet 200 $332 ;ffhiti dit ii iifiofiiiii mug 3 o 4 A moninm hydro do out ali ed sulionated d'nonyl no hthalene. 4% boned lmseed 011. 65% water 25% alkylate Sol 5 N iltralized sulion ie b dttor ns l rom the manufa eture of b enzene. vent were prepared in accordance with the method of Test stopped at 24 hours. Example I using various mixing speeds during admixture b Test stopped at 48 11mmof the water with the non-aqueous constituents. The The results show that of all the sulfonates, better corformulations were tested as in the previous examples. rosion resistance in a salt water environment is obtained Results of the tests are shown in Table V. when ammonium mahogany sulfonate is employed. This is not to be construed as meaning that the other sulfonates TABLE v are poor corrosion inhibitors however, for all of the sulfonates give satisfactory rust inhibiting properties outside St b'lt MIL-L-3150, Stirrer 3 ive eirs salt fog test of a Salt envlronment- Sample No. 982- speed, storage, results, perr.p.m. percent oil cent rust at Example VI separated 72 hours A formulation containmg 2% paraffin wax (135-137 200 15 5 F. melting point wax), 4% boiled linseed oil, 4% of a g 388 g mixture composed of 75% of a solution containing 10% 41000 2 None ammonium mahogany sulfonate in the petroleum lubricat- 21888 3 ing oil in which it was manufactured and 25% Atpet 200, 0.3% of the antioxidant, 2,6-ditertiary butyl-4-methyl 1 Brookfield counter rotating mixer with 1% blades. Approximate stirring speeds shown.

phenol, 0.5% of ortho cresol as a germacide with the balance alkylate solvent was prepared. Metal panels were coated with formulation and subjected to the salt fog test for 72 hours. No rust was found.

1 1 Example VII To the formulation of Example' VI was added 5.0% of ethylene glycol. This formulation was tested as in Example VI and similarly no rust was detected. I

It is to be understood that the antioxidant, germacide and antifreeze employed in Examples VI and- VII could be replaced by any of those listed in the specification. Similarly, the ammonium mahogany sulfonate can be replaced by a sodium aromatic sulfonate.

' It is claimed:

1. A water-in-oil emulsion consisting essentially of 50-80% water, 10-30% low-boiling petroleum hydrocarbons, 1-6% petroleum wax having a melting point of 125-140 F., and 2.0 to 6.5% of a mixture containing 4 to 6% ofa sulfonate selected'irom the group consisting of ammonium mahogany sulfonate and sodium mahogany sulfonate, -50% of a sorbitan mono-fatty acid ester and the rest a high-boiling petroleum hydrocarbon.

2. The emulsion of claim 1 containing 0.25 to 2% sorbitan mono-fatty acid ester and 0.05-1% of the mahogany sulfonate.

3. The method of preventing the corrosion of chromiumplated metal which comprises coating the chromiumplated 'metal with the emulsion of claim 5.

4. A method of preparifigth'e' water-in-oil emulsion of claim 5 which comprises heating the non aqueous constituents to a temperature of at least about 135 F. and adding to said mixture with rapid stirring the water heated to a temperature greater than about 135 F. v

5. A water-in-oil emulsion consisting essentially of about to water, about 10 to 46.7% liquid petroleum hydrocarbon, 0.3 to 10% wax, about 0.05 to 1% of a sufonate selected from the group consisting of oil-soluble ammonium aromatic sulfonatesand oil-soluble sodium aromatic sulfonates, and about 0.05 to 5% of a sorbitan mono-fatty acidester. p

6. The emulsion of claim- 5 wherein the sulfonate is a mahogany sulfonate and the mono-fatty acid ester is sorbitan monooleate present in an amount of about 0.25 to 2%.

References Cited in the file of this patent UNITED STATES PATENTS 2,560,202 Zimmer et al July 10, 1951 2,598,949 Walker et al June 3, 1952 2,716,611 Paxton Aug. 30, 1955 2,724,654 Howell et a1 Nov. 22, 1955 2,791,510 Sproule et al May 7 1957 2,911,309 Rudel et al Nov. 3, 1959 

1. A WATER-IN-OIL EMULSION CONSISTING ESSENTIALLY OF 50-80% WATER, 10-30% LOW-BOILING PETROLEUM HYDROCARBONS, 1-6% PETROLEUM WAX HAVING A MELTING POINT OF 125-140*F., AND 2.0 TO 6.5% OF A MIXTURE CONTAINING 4 TO 6% OF A SULFONATE SELECTED FROM THE GROUP CONSISTING OF AMMONIUM MAHOGANY SULFONATE AND SODIUM MAHOGANY SULFONATE, 5-50% OF A SORBITAN MONO-FATTY ACID ESTER AND THE REST A HIGH-BOILING PETROLEUM HYDROCARBON. 